Some machines, such as elevator systems, include a propulsion system having one or more linear motors to propel, for example, an elevator car in a hoistway. The linear motor may include a stationary or primary motor portion having coils or windings and a moving or secondary motor portion having one or more permanent magnets. Electrical current is provided to the primary motor portion to permit movement of the secondary motor portion within a hoistway. The primary and secondary motor portions are separated by a gap having a width sufficient to prevent contact between the two motor portions. However, the primary motor portion may experience significant thermal loads during operation, especially during peak usage such as morning and afternoon commute times in an elevator system. Thermal loads are typically significantly higher at locations having higher duty cycles and lower speeds, such as a lobby level or top floor in an elevator system.
Therefore, a need exists for a propulsion system for an elevator to reduce thermal loading on the linear motor and increase efficiency of the linear motor during operation.